The present invention is used in particular in a naturally aspirated gasoline engine. This engine has a charge movement flap (also abbreviated as CMF), which increases the movement of the charge to be ignited in the combustion chamber in its closed position. The combustion thus becomes more stable, and more exhaust gas may be recirculated in the event of an external exhaust gas recirculation system. The fuel consumption thus decreases. Since the charge movement is increased, specific operating parameters of the engine are to be adapted in accordance with the current position of the charge movement flap. These are ignition angle, variables of the air mass ascertainment, and advance angle of the injection, for example. An incorrect position of the charge movement flap accordingly also results in the engine being operated using false parameters, it also being possible in this situation that the engine will be damaged in continuous operation. Therefore, a function check of the charge movement flap is essential. Until now, the function check was predominantly fulfilled on the basis of a position feedback using sensors, as described in German Patent Application No. DE 102 08 993, for example. In contrast, German Patent Application No. DE 101 14 375, German Patent Application No. DE 101 14 376, and German Patent Application No. DE 101 64 726 suggest diagnosing the position of the charge movement flap on the basis of a knock control. German Patent Application No. DE 101 64 729 suggests diagnosing the position of the charge movement flap on the basis of uneven running.
In the method according to the related art, a separate test procedure is to be performed to ascertain a malfunction of the charge movement flap.